The problem of plastics in the ocean has been receiving a lot of attention recently. You might even say it’s “trending.” As it should be. Ideas about how to clean up the mess are circulating around the internet, including input from professional ocean scientists on how likely these ideas are to really be effective. But the cutting edge of scientific inquiry is assessing the extent to which plastics in the ocean – especially tiny fragments called microplastics – are impacting marine life. A recent study suggests it’s not just fish that might be eating plastic.
While microplastics have increasingly been documented in a range of fish from different parts of the ocean, a team from the UK has now shown that sea creatures aren’t just eating plastic, they are breathing it. In an elegant laboratory study, researchers at the University of Glasgow found that crabs exposed to microplastics uptake these particles through respiration and then retain them on their gills for as long as 3 weeks. This occurs despite the fact that crabs have a specialized appendage called a gill raker (similar to a windshield wiper) for clearing dirt and debris from crabs’ respiratory tracts.
Furthermore, crabs might get a double-whammy of plastics as researchers confirmed that crabs can also be exposed to plastics the good old fashioned way – by eating mussels (their primary food) who themselves have been contaminated with plastic as a result of filtering water for their microscopic prey.
If you are an ocean creature, there may be nowhere to hide from plastics. Whether large or small, if you make your living by filtering water for food, you could uptake plastics. If you munch prey that has taken up microplastics, you can also be exposed. And if you breathe in water through gills, as nearly all of marine life does, you also can be exposed to plastics. While scientists have now demonstrated the various mechanisms by which this exposure can occur, what remains to be uncovered is how pervasive this impact is throughout the world’s oceans and whether it poses a threat to humans who eat many of these sea creatures. Last week’s study confirms that the more we learn about plastics in the ocean, the more concerns grow.
But there are reasons to remain optimistic. The global challenge of plastic in the ocean got a big boost from Secretary Kerry’s Our Ocean Summit last month, where the topic shared the stage with other major threats like global overfishing and ocean acidification. Efforts are underway to ban some uses of plastic that harm the ocean and for which there are good substitutes; Illinois recently banned the sale of cosmetics containing synthetic microbeads, the millions of bits of plastic that escape waste water treatment facilities and find their way into the Great Lakes and the oceans. Four other states are considering similar legislation. California is considering a new trash policy, which would make preventing plastics and other materials from entering waterways a statewide priority.
Individuals can make a huge difference, too. You can sign up to clean your local beach or waterway during the International Coastal Cleanup this September 20th. And don’t forget to take the Last Straw Challenge to keep millions of straws from having a chance to find their way to the ocean.
While emerging science points to a large and growing impact of plastics on ocean wildlife, together we can all turn the tide on trash by fighting for a healthy ocean.